## How to sort a list of column vectors based on thei...

I need to sort a list of vectors, so that the vectors which have a norm of 1 come first (the order of remaining vectors is irrelevant). What would be an efficient way to do that?

## How to show the labels in DrawSubgroupLattice...

When The subgraph is too many, the label will hide automatically. Such as:

DrawSubgroupLattice(SmallGroup(200, 31), labels = ids)

But the labels is important to me. I can accept a more larger graph and more smaller text in labels. Is it possible?

## How to plot the intersections of Zc and Zs?...

How to plot  the intersection of Zc and Zs?

 (1)

## How to copy the output noramally?...

Generators(SmallGroup(60, 10))

Wii get this result:

But I hope to copy this junk information into my clipboard.

But my clipboard just get such information:

[module() ... end module,module() ... end module,module() ... end module,module() ... end module]

Or I copy it as Latex format, I will get those extra \left\right:


\left[\left(1,4,5\right)\left(2,9,10\right)\left(3,13,14\right)\left(6,17,19\right)\left(7,18,20\right)\left(8,23,24\right)
\\
\left(11,27,29\right)\left(12,28,30\right)\left(15,33,35\right)\left(16,34,36\right)\left(21,39,41\right)
\\
\left(22,40,42\right)\left(25,43,45\right)\left(26,44,46\right)\left(31,49,51\right)\left(32,50,52\right)
\\
\left(37,53,55\right)\left(38,54,56\right)\left(47,57,59\right)\left(48,58,60\right),
\\
\left(1,6,21,22,7\right)\left(2,11,31,32,12\right)\left(3,15,37,38,16\right)
\\
\left(4,17,39,40,18\right)\left(5,19,41,42,20\right)\left(8,25,47,48,26\right)
\\
\left(9,27,49,50,28\right)\left(10,29,51,52,30\right)\left(13,33,53,54,34\right)
\\
\left(14,35,55,56,36\right)\left(23,43,57,58,44\right)\left(24,45,59,60,46\right),
\\
\left(1,2\right)\left(3,8\right)\left(4,9\right)\left(5,10\right)\left(6,12\right)\left(7,11\right)\left(13,23\right)\left(14,24\right)
\\
\left(15,26\right)\left(16,25\right)\left(17,28\right)\left(18,27\right)\left(19,30\right)\left(20,29\right)\left(21,32\right)
\\
\left(22,31\right)\left(33,44\right)\left(34,43\right)\left(35,46\right)\left(36,45\right)\left(37,48\right)\left(38,47\right)
\\
\left(39,50\right)\left(40,49\right)\left(41,52\right)\left(42,51\right)\left(53,58\right)\left(54,57\right)\left(55,60\right)
\\
\left(56,59\right),
\\
\left(1,3\right)\left(2,8\right)\left(4,13\right)\left(5,14\right)\left(6,15\right)\left(7,16\right)\left(9,23\right)\left(10,24\right)
\\
\left(11,25\right)\left(12,26\right)\left(17,33\right)\left(18,34\right)\left(19,35\right)\left(20,36\right)\left(21,37\right)
\\
\left(22,38\right)\left(27,43\right)\left(28,44\right)\left(29,45\right)\left(30,46\right)\left(31,47\right)\left(32,48\right)
\\
\left(39,53\right)\left(40,54\right)\left(41,55\right)\left(42,56\right)\left(49,57\right)\left(50,58\right)\left(51,59\right)
\\
\left(52,60\right)\mathrm{
\\}\right]

But I just want to copy the output what I have seen

## How to speed up the calculation of the double inte...

I want to calculate the double integral of the following expression which includes sum of several Legendre polynomial terms, but the speed is so low. Any suggestion to speed up the calculation?

 >
 >
 >
 >
 >
 >
 >
 >
 >

## Re: How to collect using a term by multiplication ...

Hello there,

Would you allow me to ask this question?

Is there any way to apply 'collect' command using a term by multiplication of variables?

The following worksheet shows an example. What I wanted to see is the 'desired' expression, while multiple attempts with 'collect' command failed.

 > restart;
 > eq_e5_10z := Psi[q0]*Delta*delta = 1/(omega[0])*p(Delta*Psi[q])+Delta*Psi[d]+Psi[d0]*1/(omega[0])*p(Delta*delta);
 (1)
 > eq_e5_10za := Delta*Psi[d] = Psi[q0]*Delta*delta - op(1, rhs(eq_e5_10z)) - op(3, rhs(eq_e5_10z));
 (2)
 > eq_e5_10zb := subs({p(Delta*Psi[q])=0}, eq_e5_10za);
 (3)
 > collect(rhs(eq_e5_10zb), {Delta*delta});# error
 > collect(rhs(eq_e5_10zb), [Delta*delta]);# error
 > collect(rhs(eq_e5_10zb), [Delta, delta]);# did not work
 (4)
 > Desired := (psi__q0 - psi__d0*p/omega__0)*(Delta*delta);
 (5)
 >

## Fourier transform of impulse train...

I would like to compute the Fourier transform of a impulse train for applications in signal processing.  I expect to get an impulse train as a result, but do not:

restart;
delta__t:=t->sum(Dirac(t-k*T__0),k=-infinity..infinity) assuming T__0>0
with(inttrans):
S:=fourier(delta__t(t),t,omega)

I will note that Mathematica has the DiracComb function since 2008.  It also computes the result as an impulse

train:https://reference.wolfram.com/language/ref/DiracComb.html which is what I would expect.  Is there something I should be doing that I'm not aware of?

## Problem with assume - assigning values...

Why is Maple not assigning values to A and B in the below example (Maple2018)?

restart;
assume(A < B);

S := 2/(B-A);
2
S := -----
B~ - A~
B := 10; A := 5;
B := 10
A := 5
S;
2
-----
B~ - A~

## Self-intersection of vector valued function in Map...

I have been trying to figure out if there is any command in Maple where you can find the self-intersection points of a vector valued function in Maple? Other than having to type the equations manually into fsolve?

Like shown in this 2013 post.

https://math.stackexchange.com/questions/243065/self-intersection-of-vector-valued-function

## How do I calculate conjugate in partial differenti...

Hi everyone

I have a partial differential equation in function u that contains conjugate of u. How can I write PDE like this in maple

PDE:=diff(u,t)+diff(u*,x)

where u=u(x,t) is complex function and u* is conjugate.

## Why does root(-8,3) return 2(-1)^(1/3) instead of ...

Why is it not as simple as

to obtain a result for the cubic root of -8 that is what one would expect: -2?

Why doesn't Maple return -2?

## How do I solve a differential equation in Maple?...

By printing each processing step for a parametric surface entered in 3-dimensional space,

i- Finding whether the surface is a ruled(regle) surface and printing it in the ruled surface form,

ii- Calculating the dispersion parameter of the surface and the throat line,

iii- Draws the surface and the throat line on the surface together,

## CompositionSeries just work in transitive group?...

When I run this code, I will get a error information:

CompositionSeries(SmallGroup(336, 209))

It's mean this function just work in transitive group? But IsTransitive(SmallGroup(336, 209)) will get true. Is it a bug of maple? Or do I have any misunderstandings?

## densityplot legend...

Hi,

I am using the following (dummy) code to generate a density plot.

densityplot(x-y^2, x=-5..5, y=-5..5, axes=boxed, style=patchnogrid, numpoints=1000, legendstyle=[location=bottom], labels=[x, y]);

While this command does generate x vs y plots with varying color shared, I cannot figure out where the function (x-y^2) value by looking at the color shades. Is there a way to produce a legend along with the plot that will demonstrate how the function is taking different values with parameters?

I found a similar post, dated 2005, that suggests using the "s_tyle=" command. However, it does not work for some reasons. I would appreciate help in this regard.

Thank you,

Omkar